Voltage regulator device



Dec. 27, 1938. H. KOTT 2,141,654

VOLTAGE REGULATOR DEVICE Filed April 12, 1955 4 Sheets-Sheet l @J-M L040I NVENTOR.

J'QE-ZEMANN 0T7? ATTORNEYS Dec. 27, 1938. H. KOTT VOLTAGE REGULATOR DEVICE Filed April 12, 1935 4 Sheets-Sheet 2 ZO/ID INVENTOR fYZ'EMAN/Vfi fiATTORNEYS H. KOTT VOLTAGE REGULATOR DEVICE Dec. 27, 1938.

Filed April 12, 1935 I 4 Sheets-Sheet 5 v WW INVENTOR.

ATTORNEYS Dec. 27, 1938. KOTT 2,141,654

VOLTAGE REGULATOR DEVICE Filed April 12, 1955 4 Sheets-Sheet 4 5 1o 2o.50 a5 5 PAEJSU,5//V% INVENTOR.

HEEMHN/VA/O-TTI ATTORNEYS Patented Dec. 27, 1938 UNITED STATES PATENTOFFICE 2,141,654 VOLTAGE REGULATOR DEVICE Application April 12, 1935.Serial No. 15,952

4 Claims.

This invention relates to a gaseous conduction discharge device and moreparticularly to such a device adapted for use as a voltage regulatingdevice.

One of the objects of the present invention is to provide a means toregulate the voltages of a work circuit drawing current from a linecircuit of varying voltage.

Another object of this invention is to provide means to supplyrelatively small electric current at substantially constant voltage to awork circuit from a line circuit of varying voltage.

Still another object is to provide means to regulate the voltages of analternating current circuit and of a rectified electric current.

A further object is to provide an improved gaseous conduction dischargedevice adapted to be used in the regulation of the voltage 01' workcircuits.

Other objects and advantages will be apparent as the invention is morefully disclosed.

Before disclosing the present invention reference should be made to theaccompanying drawings wherein:-

Figs. 1 to 7 inclusive schematically illustrate various modified formsof the present invention and also illustrate schematically the variouselectrical circuits adapted for use therewith;

Figs. 8 and '9 illustrate one specific embodiment of the novel gaseousconduction discharge device of the present invention;

Fig. 10 illustrates a second embodiment thereof;

Fig. 11 illustrates a third embodiment thereof;

Fig. 12 illustrates graphically the operating characteristics of thegaseous conduction discharge device of the present invention; and

Figs. 1-3 to 16 other specific embodiments of the gaseous conductiondischarge device of the present invention.

In the device of the present invention, I have found that by spacing theelectrodes a desired distance apart to obtain a required breakdownpotential therebetween, and by enclosing the said spaced electrodes soas to limit the electrical discharge therebetween to a restricted pathbetween determined and approximately equal surface areas on the saidelectrodes which surface areas are arbitrarily selected to give theapproximate current carrying capacity desired and by further regulatingthe gas pressures therein within certain limits more fully hereinafterdisclosed, I am able to stabilize the gaseous discharge in said deviceover a relatively long operating life at a substantially constantoperating voltage.

I have further found that by providing a pluample, the desired currentor amperage in the rality of such spaced electrodes in parallel spacedand series relationship with the gaseous discharge therebetween confinedand restricted as above noted, I may divide or by-pass the voltage dropacross the device into a plurality of shunt circuits 5 of regulatedvoltages.

With respect to these structural modifications I have found that thecharacter and stability of the arc or glow discharge maintained betweenthe spaced electrodes in a gaseous conduction discharge device isdependent primarily on the area of the electrode surfaces upon which thedischarge locates. Where it is desired to regulate the voltage of analternating current work circuit it is highly essential that thedischarge resultant from the passage of the electric current through thegaseous conduction discharge device should be constant and stable. It isalso essential that the superposing of any rectified or direct currentin the work circuit should be avoided.

In order to accomplish both of these results I have found that thegaseous conduction discharge must be located and confined to adetermined area of the electrodes and that the respective areas of thetwo electrodes must be approximately equal.

The determined area of the electrode upon which the discharge isdirected or confined must be adapted to the purposes in view, as forexwork cireuit electrically in shunt with the discharge device. As aspecific embodiment of the present invention I will describe the same asit he ls been developed for the regulation of the v0 tage in workcircuits drawing very low amperage (or current) which is to be utilizedin the operation of photo-tubes, pyrometers, recording and measuringdevices of various types. In such devices the electric current isusually measured in terms of milliamperes or microamperes and hence anyfluctuation in the voltage of over 1 or 2% is highly undesirable.

Referring to the drawings Fig. 1 I have schematically illustrated thestructural features of my improved gaseous conduction discharge deviceand the circuit diagram showing the manner of electrically connectingthe same between a line circuit and work circuit to regulate the voltagein the work circuit.

Electrodes l and 2 are preferably disc shaped plates substantially asindicated. The surface area of the electrodes may vary widely dependingupon the desired current consumption in the said work circuit but thetwo spaced surfaces of the electrodes which preferably are in parallelspaced relationship are of approximately equal areas.

The gaseous discharge between electrodes I and 2 is confined to the twofront or facing surfaces of the electrodes I and 2 by means 6 whichcomprises substantially a tubular refractory and insulating memberidentified by numeral 6 which extends in any convenient manner aroundthe back surfaces of the electrodes I and 2 andalong the length of thelead wires 3 and l to the enclosing envelop 5, thus effectively sealingof! the electrode and lead wire surfaces except for the front facesthereof, from the atmosphere within the envelop thereby preventing thegaseous discharge from locating thereon. It is not necessary that member6 be gas impervious. It is necessary, however, that the back face of theelectrode and the lead wires be insulated so that the gaseous dischargecannot locate thereon.

The spacing between electrodes I and 2 and the areas of the front orfacing surfaces thereof .are designed to obtain suitable breakdown andoperating voltages and current carrying capacity with the particular gascomposition and gas pressures within envelop 5.

I preferably comprise electrodes I and 2 of very pure iron althoughother electrode compositions may be employed if desired, such as nickel,tungsten, molybdenum or various iron or nickel alloys. Electrodes I and2 may be surfaced with, or comprised at least in part of, one or more ofthe alkali or alkaline earth metals to lower the voltage droptherebetween and to augment the current carrying capacity of the device.

The gaseous atmosphere within envelop 5 may be comprised of any one orany desired combination of the so-called monatomic gases within certainranges of pressures, and I have found it advantageous in some instancesto incorporate therewith a small proportion of one of the moleculargases hydrogen and nitrogen which appear to increase the currentcarrying capacity of the device as well as to lower the operatingvoltage of the same. A vapor pressure of mercury also has been foundadvantageous in some instances in increasing the current carryingcapacity of the device and in lieu thereof I may utilize other metalvapors such as zinc.

The surfaces of electrodes I and 2 are preferably covered with bariumobtained, for example, by thermal decomposition of barium azide paintedthereon before assembling the electrodes I and 2 in refractorydielectric housing 6.

I have found that the provision of this housing 5 performs anotherfunction than that of confining the gaseous discharge to the opposingparallel faces of electrodes I and 2. During the passage of the gaseousdischarge the surfaces of the electrodes are subjected to bombardmentwhich progressively erodes away the surface. The metal so eroded tendsto vaporize or project beyond the field of discharge and deposit alongthe inner face of the enclosing envelop. This finely divided materialhas relatively high gas absorbing or adsorbing properties and tends toreduce the gas pressure within the device thereby rendering theoperating characteristics of the device unstable. Moreover, when asindicated the surface of the electrode is covered with a readilyvaporizable metal such as barium, this metal is similarly removed fromthe electrode surfaces and the operating characteristics of the devicethereby altered. The refractory housing 6 substantially prevents thisdissipation of the electrode surface or of the barium and confines thesame to the area included within the discharge path thus substantiallyeliminating this source of varying operating characteristics heretoforeobserved with this type of device.

As hereinabove indicated the surface area. of electrodes I and 2 uponwhich the discharge is located may vary with respect to the desiredcurrent carrying capacity of the device. By the use of barium surfacedelectrodes or by the use of mercury vapor in association with thegaseous atmosphere the required surface area may be greatly reduced, soalso when a proportion of a molecular gas such as hydrogen or nitrogenis employed.

In a work circuit wherein a maximum current of 200 milliamperes isdesired, I have found that the area of electrodes I and 2 when comprisedof pure iron may safely approximate square centimeters each. When bariumsurfaced iron electrodes are employed this area may be reduced somewhatif desired. The surface area employed for any given desired output willvary with respect to the composition of the electrode.

One of the operating characteristics of the device of the presentinvention which is distinctive from that of prior art devices is that bythus confining or restricting the discharge to determined surfaces ofthe electrodes and by preventing loss in gas pressures incident toelectrode sputtering by the use of housing 6, the burning voltage of thedevice becomes a constant over relatively wide ranges of gas pressure.However, a phenomena occurs which is not quite understood at present.During operation the gas pressure within the device increases markedlyand to such an extent that it is necessary in order to obtain stableoperation to limit the gas pressure within certain ranges which varieswith each gas and mixture of gases employed, which range can be broadlydefined as being a range of stable operation above and below which theoperating characteristics of the device are variable.

In Fig. 12 I have indicated this stable operating range of temperatureswith respect to several different gases as I have experimentallydetermined the same.

Referring to Fig. 12, I have indicated in the chart the voltage-pressurecharacteristics of the gaseous conduction discharge device of thepresent invention, in which two types of electrodes are employed incombination with several gaseous fillings. The left vertical numeralsindicate voltages and the bottom horizontal numerals indicate pressurein millimeters of mercury.

Curves a, b and 0 show the characteristics of substantially pure ironelectrodes with argon (A), helium (He) and neon (Ne) respectively.

Curves d, e, f and 9' show the characteristics of substantially pureiron surfaced or coated with barium (Ba) with helium (He) neon (Ne),argon plus 1 m. m. of helium (A-l-l m/m. He) and argon (A) respectively.

Referring to curves a, b and c, it will be noted that each curveexhibits a flattened section :c-u. As will be seen from the curves, withincrease in gas pressure the operating voltage between the spacedelectrodes drops to a certain minimum 1: and holds constant thereafterthrough a range of pressure to the point 3 thereafter the operatingvoltage abruptly changes. To obtain a constant operating voltageaccordingly the gas pressure of the device must be adjusted to notexceed the pressure at point 11. As above indicated the gas pressureincreases during operation probably as a result of heating effects inthe electrical discharge.

Accordingly, the gas pressure that is present in the device cannot be inexcess of that pressure which on increase in pressure incident tooperation substantially alters the voltage-pressure characteristics ofthe device.

When argon is employed, for example, I have found that to prevent theoperating gas pressure from exceeding about 25 millimeters the initialgas pressure should not be in excess of 10 to 12 millimeters. Withhelium the range of initial gas pressures may approximate 20 to 25millimeters as the rise in pressure is of relatively greater range; upto approximately millimeters. With neon the maximum initial pressureshould approximate 20 millimeters and the maximum operating pressureshould not exceed about 35 millimeters.

Referring to curves d, c, f and g, the effect of a surface coating ofbarium on the iron electrodes is apparent. The initial efiect is tolower the operating voltage markedly. Contrasting, for example, curve I)with curve 11, it may be seen that the barium surface has lowered theoperating voltage between the electrodes in a helium atmosphere from 150volts down to 82 volts and coincidentally therewith has lowered thepressure of the gas between points a: and y from the range 20 to 45 mm.down to about 12 to 20. With neon (curve e) however, the minimumpressure a: re-

'mains about the same (17 /2 mm.) while the upper limit has beenextended to above 55 mm. as contrasted to 35 mm. in curve 0, and theoperating voltage has been lowered to about 70 volts as contrasted to140 volts (curve c). With argon (curve g) the operating voltage has beenlowered from 175 volts (curve a) to about 68 or 69 volts and the gaspressure range from stable operation reduced to between about 4 mm. and8 mm.

Various mixtures of these gases have been heretofore proposed in the artfor use as gaseous fillings in gaseous conduction discharge devices.Each of these mixtures will exhibit a characteristic voltage-pressurecurve readily determinable by one skilled in the art. For example, argoncontaining 1 mm. pressure of helium will exhibit a curve characteristicindicated in curve f. The gas pressure for stable operation will rangefrom about '7 mm. to about 14 mm. and the operating voltage willapproximate 70 volts.

The gas filling offering the most flexibility for the purposes of thepresent invention is neon, particularly when used in combination withbarium surfaced iron electrodes as may be noted from curve c (Fig. 12).Any pressure of this gas over about 1'7 to 20 mm. and below about 40 mm.appears to satisfactorily produce the constant operating characteristicsdesired of the gaseous conduction device of the present invention. Anyof the other gases and various combinations oi these gases may beemployed however if desired without departing from the present inventionprovided the maximum gas pressure during operation lies within thepressure ranges defined by points a: and y as indicated on the curves ofFig. 12.

Referring again to Fig. l, I have schematically illustrated the voltageregulator circuit useful in connection with the present invention in itssimplest form. The gaseous conduction device A constructed ashereinabove described is shown electrically connected in parallel or inshunt with load or work circuit terminals I and 8 drawing current fromline voltage terminals 9 and I0 carrying alternating current.

The voltage in the load circuit is dependent upon the voltage dropthrough device A. In the particular instance shown device A has beendesigned to give a voltage drop of about 65 volts during operation. Thestarting voltage is somewhat higher depending upon the electrodespacing, electrode surface, gas composition and gas pressure, but isless than volts.

Limiting resistance R (or condenser C or both in series) is connectedelectrically in series with device A to regulate the voltage and currentflow through the device A and the load circuit in shunt therewith. Byincreasing or decreasing the resistance R a higher or lower currentthereby may be obtained in the load circuit.

The voltage in line circuit 9 and II) may vary from a minimum of 90volts to a maximum of volts. Due to the relatively low A. C. resistancethrough device A as compared to that in the load circuit substantiallyall of this fluctuation is taken up by device A, the voltage drop acrossterminals I and 8 in the load circuit remaining substantially constantwithin 1 or 2%.

Referring to Fig. 2, I have indicated a modification of this circuitwherein two of the devices A are utilized in series to split up thevoltage of an alternating current source into two work circuits ofsubstantially constant voltage. Devices A-A are electrically in seriesgiving a combined voltage drop therebetween of volts which is split by amid-tap connection II into two work circuits of 65 volts each. The linevoltage on terminals 8 and II) is 220 volts fluctuating ordinarily fromvolts to 240 volts. Mid-tap connection I I obvious y can be omitted ifdesired and a regulated voltage of approximately 130 volts therebyobtained.

Limiting resistance R is replaced by condenser C which operates in thesame manner as resistance R to take up the excess voltage across theline terminals 9 and I I and in addition serves to reduce the voltageloss in the circuit besides condenser C evidences substantially constantvoltage drop where resistance R may vary depending upon the currentconsumption. Obviously resistance R and condenser C may be employed inseries if desired.

Referring to Fig. 3. the circuit utilizing the present invention incombination with a transformer is illustrated. The primary (P) oftransformer (TR) having a secondary (S) in 4 to 1 ratio, for example. isconnected to terminals 9 and Ill of a 110 volt alternatin current linecircuit. The voltage on the secondary (S) of transformer (TR)approximates 400 volts.

Device A of the present invention as schematically illustrated in Fig. 3has the modified structure hereinabove described whereby a plurality ofwork circuits may be energized. A plurality of intermediate electrodeelements a. b. c are inserted between electrodes I and 2, eachelectrically connected to separate lead wires extending through envelop5 and isolated within the envelop from the electrical discharge substantally as has heretofore been described with respect to electrodes I and2. In this construction the spacings between adlacent electrodes aresubstantially as ind cated in F g. l. and the voltage drop between eachelectrode remains the same. The result obtained is a success on cf aeous discharges operating in series within a single dev ce.Substantially the same result will be obta ned if a plural ty of devicesA were c nnected in series as indicated in Fig. 2.

Load terminals 1 and 8 can then be connected to any two of theseelectrodes to obtain 65 volts or any multiple thereof depending upon thenumber of intermediate electrodes a, b and c employed. As indicatedterminal "I may be connected to electrode (a) and terminal 8 toelectrode (0) thereby obtaining 130 volts in the load circuit or, ifdesired, this may be further split into two load circuits byintermediate tap H.

Referring to Fig. 4, means to obtain a double regulation of the voltageto eliminate the small variation remaining from the use of one device Ais indicated. In this instance the voltage on line circuit terminals8Ifl is amplified by transformer (TR) to 300 volts (approximately) andthereafter is regulated by multiple electrode device A to 130 voltswhich is further regulated by a second device A substantially asindicated in Fig. l to volts on load terminals I and 8.

Referring to Fig. 5, the use of device A to regulate the voltage in thesecondary of a transformer (TR) is indicated. The device A is connectedin parallel with the primary winding P of the transformer and aninduction I2 is connected in series therewith to reduce the voltageacross device A. Most simply this may be obtained by tapping the primaryof the transformer (TR). The amplified current in secondary S will besubstantially regulated to within relatively small variations dependingupon the ratio between P and S. In the drawings the ratio is indicatedas being 1 to 2 and the voltage on secondary S therefore will be twicethat across device A and such variations of 1 to 2% will be amplifiedaccordingly. By placing a second device A in the secondary a furtherregulation as indicated in Figs. 3 and 4 may be obtained.

Referring to Fig. 6, the circuit diagram for use in regulating thealternating current to be applied to a rectifier device is indicated. Asindicated the volt A. C. from line terminals 9 and III (varying from 90to volts) is amplified by transformer (TR) and the amplified current ispassed through multiple electrode device A employing resistances RI andR2 in series therewith to limit the voltage thereon. The total voltagedrop across device A (showing five separate gaseous discharges) isapproximately 325 volts. Any intermediate voltage which is a multiple of65 volts can be obtained from device A. As indicated volts rectified A.C. is desired on terminals 1-8 of the work circuit which is obtained byconnecting electrodes (a) and (d) to the plates P-P of rectifier B, thefilament or cathode F of the rectifier being connected to the positiveterminal "I of the work circuit and the negative terminal 8 of the workcircuit being connected back to the mid-tap of the secondary ontransformer TR. Blocking condenser C is used as heretofore to suppressany A. C. surges in the rectified D. C. The use of choke coils issubstantially unnecessary in this circuit arrangernent.

Referring to Fig. 7, I have schematically indicated a circuit diagramwherein a plurality of devices A are employed in parallel with the workcircuit terminals 1 and 8 in shunt therewith whereby the currentavailable in the work circuit may be increased. Main limiting resistanceR in this case is proportionately less than when a single device A isemployed, and auxiliary resistances RI, R2 and R3 must be employed witheach tube and each of these auxiliary resistances must be larger thanmain resistance R in proportion to the number of devices A employed inparallel.

In the practical construction of device A I may employ disc electrodesas above described, enclosed in a tubular housing 8 as indicatedschematically in Figs. 1 to 7 and specifically in Figs. 10 and 11, or Imay employ concentric tubular electrodes as indicated in Figs. 13 and 14or nested cylindrical or dish shaped electrodes as indicated Figs. 8 and9, 15 and 16, or 17 and 18 respectively.

In comprising device A of disc Shaped electrodes I have found that theassembly indicated in Fig. 10 is satisfactory where only a pair ofspaced electrodes I and 2 are desired. Electrodes I and 2 are seated atthe ends of tubular envelop 5 in dielectric insulating material 8 whichentirely fills the tapered end of envelop 8 leading to press II throughwhich extend lead wires 3 and 4 connected respectively to electrodes Iand 2. In this manner the entire discharge is limited to the facingsurfaces of electrodes I and 2. Where relatively close spacing ofelectrodes I and 2 is desired however, the assembly indicated in Fig. 11is preferred.

In Fig. 11 the disc electrodes I and 2 with any number of intermediateelectrodes 0, b, c, etc., are piled one above the other with spacerelements 30 therebetween to give the desired spacing. The bottomelectrode I rests upon the plate insulator 3| and is connected to leadwire 3 passing therethrough, Tubular insulator 6 encloses the pile ofelectrodes I, 2, a, b, c and is sealed or otherwise joined to plateinsulator 3| and the upper surface of electrode 2 is coated withinsulation 82 serving to hold the entire structure rigidly. Plateinsulator 3| is supported by support wires I5 above press II and leadwires for each of the electrodes pass through the press to therespective electrodes through small openings in tubular insulator 6,each lead wire being insulated its entire length from electricaldischarges. The entire assembly then is sealed within an enclosingenvelop 5 in a manner heretofore known in the art.

When nested electrodes are employed housing 6 is flat rather thantubular as with disc electrodes, and is provided with concentric groovesI2 into which the open ends of the electrodes are inserted and sealedtherein as indicated at II. Lead wires I4 of the electrodes extendthrough press II and housing 6' and are electrically connected to theelectrodes in any convenient manner as by spot welding and the entirelength of said lead wires I4 down to the press II is insulated in anysuitable manner from the gaseous atmosphere so as to confine anyelectrical discharge to the metal surfaces of the electrodes. v

Support wires I5 are provided to support the assembly of nestedelectrodes and housing 6 above the press II. The press II is sealed atI6 as heretofore practiced in the art with enclosing envelop 5 andexhaust tube I1 is provided through the press to evacuate the interiorof the envelop and to fill the same with a desired gaseous filling atthe desired pressure. Before assembling the nested electrodes in themanner shown the surfaces thereof are coated with barium azide andduring the exhaust procedure the electrodes are heated by induction tobreak down the azide leaving pure barium on the said surfaces. Theprecise spacing of the nested electrode surfaces and the gas pressureswithin the envelop are selected as hereinabove described to give thedesired operating characteristics.

In the construction shown in Figs. 13 and 14 the ends of the concentrictubular electrodes are closed by plug members I8 comprised ofdielecrelationship. The plugs it are supported by support wires 20 overpress H and lead wires 2| extend through the press II and areelectrically connected to the electrodes 1 and 2 but the length thereofinside of envelop 5 is insulated from any .electrical discharge locatingthereon.

The modifications of [5 and I6 respectively of the electrode structureof Figs. 8 and 9 illustrate different shapes of nested electrodesapplicable in the present invention.

Having broadly and specifically described the present invention andindicated several modifications thereof, it is apparent that the samemay be widely adapted and modified without departing from the nature andscope thereof as may be included within the accompanying claims.

What I claim is:

1. A gaseous conduction discharge device comprising a hermeticallysealer" envelope, an electrically conductive gas within said envelope,electrodes of the cold eiectrode type enclosed within said envelope,each said electrode being substantially identical in size, shap: andconfiguration, means to sustain said electrodes within said envelopewith substantially equal surface areas thereof in opposite spacedrelation, lead wires extending through the envelope and connected toeach said electrode, and dielectric insulating material enclosing thelength'of said lead wires within the said envelope and part of saidelectrodes to restrict any gaseous conduction discharge between saidelectrodes to the said opposite surfaces of substantially equal surfaceareas.

2. The device of claim 1, the said gas being comprised of neon at apressure above about 17 mm. and not in excess of about 35 mm.

8. The device of claim 1, wherein the said equal surfaces of saidelectrodes are comprised of substantially pure iron and the said equalsurface areas of the said electrode are covered with barium and the saidgas consists of neon at a pressure above about 17 mm. and not in excessof about 55 mm.

4; The device of claim 1, wherein said electrodes consist of a pluralityof substantially identic: 31y shaped electrodes nesting one within theother in spaced relation, the opposing surfaces of said nestedelectrodes being surfaced with barium and the said gas consisting ofneon at a pressure in excess of about 17 mm. but not in excess of aboutmm.

HERMANN KO'I'I.

